interface DataOption {
    public void dataSelect();

    public void dataAdd();

    public void dataDel();
}

class DataManagement implements DataOption {
    public void dataSelect() {
        System.out.println("查询数据");
    }

    public void dataAdd() {
        System.out.println("添加数据");
    }

    public void dataDel() {
        System.out.println("删除数据");
    }
}

public class example3_18 {
    public static void main(String args[]) {
        DataManagement data = new DataManagement();
        data.dataSelect();
        data.dataAdd();
        data.dataDel();
    }
}
